The subject invention is directed to the art of emission control devices and, more particularly, to a system and an improved article, the metallurgical composition and structure of which are particularly suited for reducing the oxides of nitrogen, especially nitric oxide and nitrogen dioxide (herein collectively referred to as NO.sub.x), which are commonly found in the exhaust gases emanating from an internal combustion engine.
More particularly, the invention concerns a system for the removal of significant amounts of NO.sub.x from the exhaust gases of the internal combustion engine which includes the use of a catalytic structure which can be mounted in the exhaust system of an internal combustion engine and which is characterized by its corrosion resistance and its efficacy in reducing the various oxides of nitrogen (NO.sub.x) at temperatures of about 1100.degree. F. and above.
The invention further relates to a system of operating an internal combustion engine and includes the use of a catalytic structure capable of reducing oxides of nitrogen, from the exhaust gases of an internal combustion engine. In addition, it concerns a catalytic structure comprising a durable, corrosion resistant metal substrate having an effective amount of a NO.sub.x reducing catalyst metallurgically bonded thereto.
This invention also relates to a method of manufacturing a corrosion resistant catalytic structure which is capable of catalytically reducing oxides of nitrogen found in the exhaust gases of an internal combustion engine. In particular, the invention concerns a method of manufacturing a thin, low mass, high surface area expanded metal structure which is capable of catalytically reducing NO.sub.x comprising a durable, corrosion resistant nickel, cobalt or iron base substrate or support having an effective amount of an NO.sub.x reducing catalyst adherently deposited on at least part of the surface of the substrate or support.